Flotation of minerals



. SAYRLI, OF PETTSBUBGE, PENNSYLVANIA, ASSIG-NOR TU METALS RECOVERY CfJI'IPf-LNY, G'E NE'W YORK, N. Y., A CORPORATION OF MAINE.

FLOTATION Q1 MINERALS.

Brewing.

Application filed July 2,

all w from may coacem Be known that l, RALPH E. Saran, a "'zen of the United States, residing at in the county of Allegheny, of Pennsylvania, have invented certain new and useful Improvements in the Flotation of l linerals; and 1 do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use thesame.

This invention relates to the concentration of: minerals, such as sulfid ores and the like, by flotation.

The invention is based upon the discovery that the flotation operation can, in many cases, be improved by the addition to the ore or mineral pulp of a dihydric alcohol or pinacone, for example, ordinary pinacone (tetramethylethyleneglycol). Ordinary pinaccne appears to have little it any selective action in bringing about the flotation of the mineral, but it has marked frothing qualities and provides an appropriate amount pf froth with an ore pulp containing a suitable selective or collecting agent but lacking in frothing qualities, or an ore pulp which requires no added selective agent but is lacking in frothing qualities. The pinacone may thus be used to advantage with flotation agents which have marked selectiye or collecting properties but which are devoid of, or deficient in, frothing qualities.

The dihydric alcohols or pinacones can he producer. in suitable way. For example. acetone or methylethylkctone can be subjected to reduction, with suitable reducing agents, to gi e he corresponding pinacones. Acetone will hus give ordinary pinacone or tetramethylethyleneglycol having the following formula:

(CH .CUHCOH. (CH 2 'iacone is a crystalline solid, which a. 'drate, also crystalline. hither ons pinacone or the hydrate can b in eouivalent amount. It is not n u the pinacone to be isolated and obtained in a pure state, but it can be used 'n admixture with other reduction products w ieh may also contribute to the flotation operation.

The pinacone can be incorporated with the ore or mineral pulp in any suitable manner Specification of Letters Patent.

Patented Mar. 1, 1921.

1920. serial No. 393,605.

which will insure its uniform incorporation and dissemination throughout the pulp. It may thus be incorporated by adding to the grinding mill, in which the ore is ground, or it can be added after the grinding operation and during or prior to the flotation operation. The flotation operation can be carried out in any suitable apparatus, such as an ordinary Callow cell, or in apparatus where the air is incorporated in the ore pulp by mechanical agitation.

It is of advantage in many cases, as with certain copper ores, to add to the ore pulp a small amount of alkali, which may be sufticient in amount to give to the ore pulp a distinct alkaline reaction. lVhen alkalis are used, it is desirable to give them an appreciable time of contact with the ore pulp before subjecting the latter to flotation. The alkalis can thus be added with advantage 'in the grinding mill so that they will. be present during the grinding operation. The alkali may be caustic alkali such as sodium hydrate, or an alkaline salt, such as sodium carbonate, or even lime or calcium .oxid or hydrate can be used.

The amount oi the dihydric alcohol added can vary somewhat, and may be as little as one-fifth of a pound per ton of ore (that is, calculated on the weight of the ore and not i the ore pulp}. Larger amounts may, however, be used, as well as even'smaller amounts in some cases.

The invention will be further illustrated by the following specific examples of tests made upon a copper sulfid ore:

Ema/02 010 1-500 parts by weight of Utah Copper Companys ore was ground in a pebble mill with 250 parts of water, lime equivalent to tour pounds per ton of dry ore, and thiocarbanilid equivalent to onefifth pound per ton. The ground pulp was transferred to a (allow rougher cell, diluted and floated after the addition of about parts of water to which had been added pinacone equivalent to three-tenths pound per ton of dry ore. A satisfactory froth was produced at. once. Aeration of the pulp was continued until the concentration of the sulfid mineral practically ceased. A satisfactory concentrate and higgi recovery were obtained.

Example 2.-The treatment was similar to that of Example 1 exeept'that cliazcr.

aminobenzene equivalent'to one-fifth pound per. ton of dr ore was used in place of the thiocarbanili With an ore of the character referred to in the above examples, it is of importance to provide a selective or collecting 8. nt to supplement the action of the dihydnc alcohol, which appears to be essentially that of a frothing agent with but little selective or collecting properties. Where, howevet) the ore pulp contains an appropriate selective or collecting agent, or inherently reduires the addition of no such agent but is deficient in frothing qualities, the ,addition of -dihy dric alcohol, in a manner similar to that above described, imparts the desired frothing qualities and provides bubbles in a suflicient quantity and of suflicient persistency to overfldw into the launder of the flotation machine thereb mechanically facilitating the removal of t e mineral concentrate.

It will be evident that, where selective or collecting agents are required, diflerent agents may be used having; the desired selective or collecting or mineral-modifying properties. Certain of these a ents, such as thiocarbanilid and diazoamino enzene, have V ver marked selective or collecting or minera -modifyirag :ialities, but are substantiall devoid of frothing ualities. The use of dihydric alcohol, accor ing to the present invention is therefore of particular value in connection with the use of flotation agents of this character. The present invention can, however, be carried out with the use bi other flotation agents, which may have both selective or collecting and frothing qualities, but which are deficieiit in frothing qualities and the requisite frothing properties can be imparted by the addition of the dih dric alcohol in a manner similar to that a ove de scribed.

I claim:

1. The method of effecting the concentration of minerals by flotation, which comprises adding to the mineral pulp a small amountof a dihydric alcohol, and subjecting the resulting mixture to a flotation operation; substantially as described.

2. The method of effecting the concentration of minerals by flotation, which comprises adding to the mineral pulp a small amount of a selective or collecting or minoral-modifying agent, deficient in frothing 4. The method of efl'e'cting the concentration of copper sulfid ores by flotation, which comprises adding to the mineral pulp a small amount of an alkali, a small amount of a flotation agent deficient in frothing properties, and a small amount of a dihydric alcohol, and subjecting the resulting mixture to a flotation operation; substantially as described.

5. The method of effecting the concentration of minerals by flotation, which comprises adding to the mineral pulp a small amount of a pinacone, and subjecting the i'esulting'mixture to a flotation operation;

substantially as described.-

6. The method of effecting the concentra-n tion of minerals by flotation, which com- ,prises adding to the mineral pulp a small amount of a selective or collecting or. mineral-modifying agent, deficient i'n frething qualities, together with a small amount of a pinacone, and subjecting the resulting mixture to a flotation operation; substantially as described.

7. The method of effecting the concentration of copper sulfld ores by flotation, which comprises adding to the mineral pulp a small amount of an alkali and a small amount of a pinacone, and subjecting the resulting mixture to a flotation operation; substantially as described.

8. The method of effecting the concentration of copper suli'id ores by flotation, which comprises adding to the mineral pulp a small amount of an alkali, a small amount of a flotation agent deficient in frothing properties, and a small amount of a pinaconc, and subjecting the resulting mixture to a flotation operation: substantially as described.

In testimony whereof I aflix my signature.

RALPH E. SAYRE. 

